1. Field of the Invention
The present invention relates to a printer, a printer head, and a manufacturing method for the printer head, and can be applied in, for example, thermal type ink-jet printers.
2. Description of the Related Art
In recent years, in the field of image processing and the like, there has been increased needs for color hard copies. Conventionally, the sublimation thermal transfer method, the fusing thermal transfer method, the ink-jet method, the electro-photography method, the heat-developing silver-salt method, and other like color hard copying methods have been proposed to deal with such needs.
Of these methods, the ink-jet method can output high-quality images with a simple configuration. The reason is that this method causes droplets of a recording fluid (ink) to fly from nozzles provided on a recording head, which adhere to the object of recording and form dots. The ink-jet method is classified into the electrostatic gravitation method, the continuous vibration generating method (piezo method), the thermal method, etc., according to differences in the method of causing the ink to fly.
Of these methods, the thermal method is a method wherein bubbles are generated by local heating of ink, and ink is pressed out from nozzles which are discharging orifices, by these bubbles, thereby causing the ink to fly to the printing medium. Accordingly, color images can be printed with a simple configuration.
A thermal printer is configured using a so-called printer-head. The printer head is arranged such that heat-generating elements for heating ink, transistors for driving the heat-generating elements, and so forth, are mounted on the printer head.
Now, the heat-generating elements are formed by depositing a resistor material such as tantalum, tantalum aluminum, titanium nitride, etc., on a predetermined substrate by sputtering, which is widely used in semiconductor forming processes, forming aluminum electrodes thereupon, following which a protective layer of a silicon nitride film or the like is formed. The printer head has a cavitation-resistant layer, ink liquid chambers, and nozzles formed of a tantalum film on the upper layer of this protective layer, thereby enabling ink in the ink liquid chambers to be heated by the heating of the heat-generating elements. Further, the printer head is arranged such that electric power can be supplied to the heat-generating elements from MOS (Metal Oxide Semiconductor) or bipolar transistors, and further configured so as to control the operation of the transistors by predetermined driving circuits, thereby driving with driving circuits to adhere ink liquid drops on paper.
Now, with the heat-generating elements at the time of printing, electricity is repeatedly applied by pulse voltage being repeatedly applied. With conventional printer heads, the repeated application of electricity may change the resistance value and eventually lead to line breakage of resistor elements, and accordingly reliability has been insufficient.
The present invention has been made in light of the above, and accordingly it is an object thereof to provide a printer, a printer head, and a manufacturing method for the printer head, for improving the reliability of heat-generating elements over that of conventional arrangements.
In order to solve the problems, with the present invention, application is made to a printer, printer head, and a manufacturing method for the printer head, and the heat-generating element is formed by depositing at least a IV A metal layer or a V A metal layer, followed by depositing a resistor material upon this metal layer.
According to the present invention, a IV A metal layer or V A metal layer is introduced between these, and the IV A metal layer or V A metal layer closely adheres with sufficient strength to the lower layer which is silicon nitride film, silicon oxide film, etc., due to forming compounds therewith and the interface, and also closely adheres with sufficient strength to the upper layer of TiN or the like making of the heat-generating elements, due to being metal material of the same type. Thus, even in the event that thermal stress is repeated, peeling off of the heat-generating elements can be prevented, and the reliability of the heat-generating element can be improved over conventional arrangements.